JP2001153555A - Sludge granulating and drying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sludge granulating and drying device, capable of manufacturing granulated and dried sludge, containing good quality carbide obtained by mixing sludge to be dried into the carbide sufficiently, stably and nicely at a low cost, while capable of being facilitated in the control of operation and reduced in the control of maintenance. SOLUTION: The sludge granulating and drying device is a device for manufacturing granulated and dried sludge, containing carbide, and is constituted substantially of a sludge granulating and drying process 10, a sludge to be dried supplying process 11 for supplying the sludge to be dried into the sludge granulating and drying process 10, and a carbide supplying process 12, supplying the carbide to the sludge granulating and drying process 10 and/or the sludge to be dried supplying process 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sludge granulation / drying apparatus for producing granulated dry sludge containing carbide (hereinafter, simply referred to as sludge granulation / drying apparatus).

[0002]

2. Description of the Related Art Conventionally, organic sludge discharged from a wastewater treatment facility or the like is usually added with a flocculant to coagulate it and then dewatered to dehydrated sludge for reduction and stabilization.
Dewatered sludge was landfilled directly or landfilled after incineration. However, in recent years, from the viewpoint of shortage of landfill sites and the reuse of resources, dehydrated sludge is dried and then fermented aerobically into compost (compost), which is mainly used as fertilizer and land improvement material for green farmland. It has come to be used effectively. And
As shown in FIGS. 6 and 7, a dehydrated sludge is mixed with a carbide effective as a soil conditioner to produce a granular dry sludge containing the carbide, which is fermented to have excellent air permeability and excellent handleability. It has also begun to produce high quality compost.

FIG. 6 is a block diagram showing one conventional method for obtaining granulated dry sludge. In FIG. 6, 1 is a sludge dewatering machine, 2 is a carbonization device, 3 is a mixer, 4 is a dryer, and 5 is a granulator.

Next, the operation will be described. First, the sludge is dewatered by the sludge dewatering machine 1 to a water content of about 85% to become a pudding-like dewatered sludge, and supplied to the mixer 3. On the other hand, low-moisture organic substances such as rice husks, sawdust, garbage and the like are carbonized by the carbonization device 2 to become granular carbides having a water content of about 10%, and supplied to the mixer 3. In the mixer 3, the dewatered sludge and the carbide are mixed to form a mixed dewatered sludge having a water content of about 75%, and the mixed water is supplied to the dryer 4. In the dryer 4, the mixed dewatered sludge is dried to become dried sludge having a water content of about 60% to 30%, and supplied to the granulator 5 to be granulated to become granulated dry sludge, which is mainly composed of raw materials such as compost. Used for

FIG. 7 is a block diagram showing another conventional method for obtaining granulated dry sludge. Note that among the devices used in the conventional method, those that are common to the devices used in the conventional method shown in FIG.

The conventional method shown in FIG. 7 is different from the conventional method shown in FIG. 6 in that the dewatered sludge is supplied to the dryer 4 prior to the mixer 3, except that it is different from the conventional method shown in FIG. Have in common. That is, the pudding-like dewatered sludge dewatered by the sludge dewatering machine 1 to a water content of about 85% is supplied to the dryer 4 to be dried sludge having a water content of about 60% to 30%, and then mixed with the mixer 3
Supplied to On the other hand, low-moisture organic substances such as rice husks, sawdust, garbage and the like are carbonized by the carbonization device 2 to be carbonized with a water content of about 10%, and supplied to the mixer 3. After the dry sludge and the carbide are mixed in the mixer 3, the mixture is supplied to the dryer 4 and becomes mixed dry sludge. The mixed dried sludge is supplied to the granulator 5 and granulated to become granulated dry sludge, which is mainly used as a raw material such as compost.

[0007]

In any of the above-mentioned conventional methods, it is necessary to use a dedicated device for each processing, such as the mixer 3, the dryer 4, and the granulator 5, and construction costs and equipment costs are required. And a large installation space was required.
In addition, the operation management of each unit is required, which complicates the operation and is difficult to control, and in addition, the operation and maintenance such as maintenance and the burden of costs are large. Furthermore, in order to stably produce good-quality granulated dry sludge with a desired water content, it is necessary to sufficiently consider the water content and input amount of the carbide and the sludge to be dried, and the drying time and temperature. However, there is a problem that the burden on the operator is large. In addition, there is also a problem that unless the to-be-dried sludge and the carbide are sufficiently mixed and stirred, it is not possible to efficiently produce a uniform granulated and dried sludge.

[0008]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and can stably produce granulated dry sludge containing carbide in a good and inexpensive manner. It is still another object of the present invention to provide a sludge granulation / drying apparatus capable of easily producing a granulated dry sludge having a desired moisture content, with easy operation control of granulation and the like.

A sludge granulation and drying apparatus according to the present invention comprises a drying tank having a heat transfer surface, a heating section for heating the heat transfer surface of the drying tank, a rotating shaft provided inside the drying tank, and a rotating shaft. A sludge granulation and drying step comprising a plurality of rotating blades supported on a shaft and transporting the dried sludge to the upper part of the drying tank while contacting the heat transfer surface, and a driving unit for rotating the rotating shaft; A sludge supply step of supplying sludge to be dried to the drying step, and a carbide supply step of supplying carbide to the sludge granulation and drying step and / or the sludge supply step are provided.

Here, a basic configuration 1 of a sludge granulation and drying apparatus according to the present invention will be described with reference to FIG. This basic structure 1 corresponds to the invention of claim 1, and comprises a sludge granulation and drying step 10, a dry sludge supply step 11 for supplying the sludge to be dried to the sludge granulation and drying step 10, Granulation drying step 10 and / or drying sludge supply step 1
1 and a carbide supply step 12 for supplying carbides.

The sludge granulation and drying process 10 is a step for granulating and drying the sludge to be dried, and includes a drying tank (not shown) having a heat transfer surface (not shown) for drying the sludge to be dried, and a transfer tank. A heating unit (not shown) for heating the hot surface, a rotating shaft (not shown) provided in the drying chamber, and the sludge to be dried supported on the rotating shaft and brought into contact with the heat transfer surface, is carried to the upper portion of the drying tank. It is implemented by a plurality of rotating blades (not shown) and a driving unit (not shown) for rotating a rotating shaft. In order to carry out the sludge granulation drying step 10, for example, a granulation dryer (refer to FIG. 4) marketed by the present applicant under the trademark "SUN ES DRYER" is optimal.

In the sludge supplying step 11 to be dried, for example, the sludge dehydrated by a centrifugal dehydrator or a belt press type dehydrator or the like is used alone or together with carbide to form a sludge granulation and drying step 10.
Is to be supplied. The carbide supplied from the carbide supply step 12 is desirably in the form of granules. However, even if it is a lump, it is easily crushed by the rotating means in the sludge granulation and drying step 10 to be granulated or powdered. Granular or powdery carbides become the core of the granulated dry sludge finally obtained, and contribute to the granulation of the dried sludge by adhering the sludge around it.

Further, the sludge granulation drying apparatus according to the present invention comprises a drying tank having a heat transfer surface, a heating section for heating the heat transfer surface of the drying tank, and a rotating shaft provided inside the drying tank. A sludge granulation and drying process comprising a plurality of rotating blades supported by the rotating shaft and transporting the sludge to be dried to the upper part of the drying tank while contacting the heat transfer surface, and a driving unit for rotating the rotating shaft; A sludge supply step of supplying sludge to be dried to the granulation and drying step, a carbonization step of carbonizing organic matter, and a carbide supply of supplying the carbide generated in the carbonization step to the sludge granulation and drying step and / or the sludge supply step And a heat source supply step of supplying heat energy discharged from the carbonization step to the heating section in the sludge granulation and drying step.

Here, the basic configuration 2 of the sludge granulation and drying apparatus according to the present invention will be described with reference to FIG. This basic structure 2 corresponds to the invention described in claim 2, and in addition to the sludge granulation and drying step 10, the sludge to be dried supply step 11 and the carbide supply step 12, a carbide formed by carbonizing an organic substance to produce a carbide. It further includes a generation step 13 and a heat source supply step 14 for supplying waste heat from the carbide generation step 13 as heat energy to the heating section of the sludge granulation and drying step 10. The carbide generated in the carbide generation step 13 is supplied to the sludge granulation and drying step 10 and / or the dried sludge supply step 11 by the carbide supply step 12, and the waste heat discharged from the carbide generation step 13 is converted to the sludge granulation and drying step. The heat is supplied to the ten heat transfer means as thermal energy, and the energy is effectively used. The heat energy supplied through the heat source supply step 14 can be in the form of a dry gas having steam and / or waste heat, but is not limited thereto.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 3 is a block diagram showing a first embodiment of a sludge granulation and drying apparatus according to the present invention, and FIG. 4 is a block diagram showing a drying and sludge granulating and drying process in the sludge granulation and drying apparatus shown in FIG. FIG. 5 is a perspective view specifically showing the configuration of the mixing device, and FIG. 5 is a schematic diagram showing a state of granulation by dehydrated sludge and carbide by the sludge granulation and drying device according to the present invention.

The first embodiment substantially corresponds to the basic configuration 2 of the sludge granulation and drying apparatus according to the present invention shown in FIG. In FIG. 3, reference numeral 20 denotes a granulation dryer for performing the sludge granulation drying step 10 shown in FIG. 2 and the like.
A granulation dryer commercially available from the above can be suitably used.
As shown in FIG. 4, the granulated dryer 20 has a bottomed cylinder functioning as a drying tank and having an inner peripheral surface 21a serving as a heat transfer surface that comes into contact with sludge to be dried put into the drying tank. A steam jacket 22 as a heating unit attached to the outer peripheral surface of the casing 21 and heating the inner peripheral surface 21a side; and a steam inlet 23 provided at an upper portion of the steam jacket 22; The steam jacket 22
, A dewatered sludge supply pipe 25 for penetrating the lower part of the steam jacket 22 and supplying dewatered sludge into the casing 21, and a casing penetrating the lower part of the steam jacket 22. A discharge conveyer 26 for discharging the dried sludge from the inside 21, a sludge discharge port 27 provided at the end of the discharge conveyer 26, and a coaxially disposed central part in the casing 21 and a bottom part of the casing 21. Shaft 28 having a length from the top to the top
And a granulating fin 30 serving as a rotating blade spirally wound around the rotating shaft 28 supported by the distal ends of a plurality of arms 29 projecting radially outward from the outer peripheral portion of the rotating shaft 28.
And a drive motor 31 serving as a drive unit for rotatingly driving the rotary shaft 28 and the granulation fins 30 in the direction of arrow A, and using the rotational force of the drive motor 31 to deposit dehydrated sludge deposited near the bottom of the casing 21. Rake 32 for scooping
A baffle 33 for dropping the dried sludge deposited to an upper inside portion of the casing 21; and a steam exhauster provided at the upper portion of the casing 21 for discharging steam released by drying the dehydrated sludge as exhaust gas. Exit 34
It is roughly constituted from. The granulation fin 30 is rotatable so that its outer peripheral edge is close to the inner peripheral surface of the casing 21.

As shown in FIG. 3, the granulating dryer 20 having the above-described structure includes a premixing hopper 40 for premixing the materials before the materials are charged, and granulating the material in the premixing hopper 40. Dewatered sludge supply pipe 2 for transfer into dryer 20
5 and a transfer conveyor 41 connected thereto.

The sludge supply step 11 in the first embodiment includes a centrifugal dewatering machine 42 shown in FIG. 3 and a dewatering cake storage hopper for storing the dewatered cake obtained by dewatering by the centrifugal dewatering machine 42. 43 and a dewatering cake transfer conveyor 44 for transferring the dewatered sludge stored in the dewatering cake storage hopper 43 to the premixing hopper 40.

The carbide generating step 13 in the first embodiment is configured to be performed by a carbonizing furnace 45 shown in FIG. 3, and the carbide supplying step 12 stores the carbide generated in the carbonizing furnace 45. And a carbide storage hopper 46 from the carbonization furnace 45.
And a second carbide transfer conveyor 48 for transferring carbides from the carbide storage hopper 46 to the premixing hopper 40. I have.

Heat source supply step 1 in the first embodiment
Reference numeral 4 denotes a heat exchanger 49 for exchanging heat using waste heat discharged from the carbonization furnace 45, and a heat jacket extracted from the heat exchanger 49 by a steam jacket of the granulation dryer 20 shown in FIG. It is configured to be implemented by a heat energy supply pipe 50 for supplying the fuel to the fuel cell 22 through the steam inlet 23.

Next, the operation will be described. First, the sludge to be dried generated in the wastewater treatment or the like is supplied to the centrifugal dewatering machine 42, dewatered to a water content of about 85% under predetermined operating conditions, and converted into a pudding-like dewatered sludge.
It is discharged to 3. Here, the pudding-like dewatered sludge refers to sludge having some formability and elasticity like an agar, and relatively poor fluidity. The pudding-like dewatered sludge is supplied to the granulating dryer 20 via the premixing hopper 40 and the transfer conveyor 41 by the dewatering cake transfer conveyor 44. Prior to the supply of the dewatered sludge, waste heat from the carbonizing furnace 45 shown in FIG.
2 while heating the inner peripheral surface 21a of the casing 21 and driving the drive motor 31 to rotate the rotary shaft 28 with the arrow A
Rotate at high speed in the direction.

In this state, when a predetermined amount of dewatered sludge is supplied from the dewatered sludge supply pipe 25, the dewatered sludge is centrifuged by the granulation fins 30 as shown in FIG.
Of the granulation fin 30 and the rotating shaft 28 and a gap (notch) formed between the granulation fins 30 mainly. Then, it falls on the upper surface of the lower granulation fin 30 and rises again, or falls to the bottom surface of the casing 21. The falling sludge to be dried collides with a plurality of rotating granulation fins 30 and is repeatedly crushed by the impact thereof, or crushed by falling to the bottom surface. The sludge to be dried which has dropped to the bottom surface of the casing 21 is scooped up by the rake 32 at the lowermost portion, and starts to rise again, and repeats the above-described fall and re-rise. The raised sludge to be dried is sequentially scooped up by the granulation fins 30 in the upper stage and rises. However, since the granulation fins 30 are provided independently of each other, a part of the sludge to be dried falls. The sludge to be dried is circulated up and down in the casing 21 by repeating such an operation.

On the other hand, low-moisture organic matter is carbonized in a carbonization furnace 45 to a water content of about 5 to 15% under predetermined operating conditions.
The first carbide transfer conveyor 47 converts the carbide storage hopper 4 into granular carbide having a particle size of about 1 to 10 mm.
6, the carbide is further sent to the premixing hopper 40 by the second carbide transfer conveyor 48, and further supplied to the granulation dryer 20 via the transfer conveyor 41. The carbide thus supplied is sufficiently mixed with the sludge to be dried while circulating vertically in the casing 21 by the rotating granulating fins 30 and the like, and a mixture of the sludge to be dried and the carbide (hereinafter, referred to as a sludge mixture). And circulates vertically within the casing 21.

The sludge mixture that has fallen to the bottom of the casing 21 is crushed by the impact of the rotating granulating fins 30 and further by the collision with the bottom surface, so that the sludge mixture adheres and solidifies in the casing 21 or agglomerates. Can be prevented. When the sludge mixture circulates up and down within the casing 21, the sludge mixture contacts the inner peripheral surface 21a of the casing 21 heated by the steam jacket 22 in a state where the sludge mixture is pressed against the inner peripheral surface 21a and releases steam. % To 20
%, And it becomes granulated dry sludge which is further pulverized and granulated.

In this granulation, as shown in FIG. 5, when the purine-like dehydrated sludge and the carbide are sufficiently mixed, the granular carbide becomes a nucleus, and the peripheral surface of the carbide is covered with the dehydrated sludge. Is achieved by In this granulation, since the particle size of the carbide itself is small, the particle size of the obtained granulated dry sludge is also 3 m.
m to about 15 mm, and the granulation fins 3
Since the agitation / mixing power of 0 is large, the agitation / mixing of the sludge mixture during granulation proceeds, and a uniform and easy-to-handle granulated dry sludge can be obtained.

As described above, according to the first embodiment, the sludge to be dried is subjected to the respective processes of drying, mixing, and granulation using one granulation dryer 20. The granulated dry sludge can be produced stably and favorably at low cost without installing a dedicated device required for each treatment in the conventional method, and the operation management is easy and easy to control.

Further, according to the first embodiment, since the carbide is supplied into the casing 21 of the granulation dryer 20, the sludge is attached to the peripheral surface of the granulation dryer 20 by using the carbide as a nucleus. Dry sludge can be easily obtained.
The obtained granulated dry sludge can suppress odor by the effect of adsorbing carbides, and can further improve epidemiological safety by composting. In the first embodiment, the carbide is used together with dehydrated sludge as the sludge to be dried.
After pre-mixing in the pre-mixing hopper 40, both were supplied as a mixture into the casing 21 of the granulation dryer 20, but the carbide was directly introduced into the casing 21 without passing through the pre-mixing hopper 40. You may comprise so that it may supply.

In the first embodiment, the steam jacket 22 is provided as a heating unit for heating the inner peripheral surface 21a of the casing 21 which is a heat transfer surface for the sludge to be dried.
A structure such as the steam jacket 22 which can introduce or circulate a heat medium may be used, or an electric heater or a combustion burner which can directly heat the heat transfer surface may be used. In any case, any configuration may be used as long as the temperature of the heat transfer surface can be adjusted and granulated dry sludge having a predetermined moisture content can be obtained.

In the first embodiment, the carbide is mixed with the dewatered sludge in the premixing hopper 40 and then introduced into the chamber of the granulation dryer 20. The pre-mixing hopper 40
May be directly introduced into the chamber of the granulation dryer 20 without passing through.

Further, in the first embodiment, the granulation dryer 20 is configured to mix the carbide together with the dehydrated sludge. However, in addition to the carbide, a fertilizing component such as nitrogen, phosphorus or potassium is added and mixed. Is also good. In this case, the fertilizing component may be introduced into both the premixing hopper 40 and the chamber of the granulation dryer 20 as in the case of the above-mentioned carbide, or may be directly granulated and dried without passing through the premixing hopper 40. It may be introduced into the chamber of the machine 20. The obtained granulated dry sludge can be used as a granular fertilizer.

The granulating fins 30 are spirally provided along the heat transfer surface in the casing 21 and may be constituted by continuous spiral blades, and may be cut off in the middle to form a plurality of rotating blades. The plurality of rotating blades may be arranged so as to be entirely spiral. Thus, the granulation fin 3
The presence of a plurality of 0s increases the number of times that the dewatered sludge being dried at the discontinued portion falls to the bottom of the casing 21 and rises again while being dried along the granulation fins 30, thereby increasing the drying effect. Is obtained.

[0032]

As described above, according to the present invention, the mixing and stirring of the sludge to be dried and the carbide and the drying, crushing and granulation of the sludge mixture are performed in one sludge granulation drying step. In the conventional method, there is no need to separately install dedicated processing equipment required for each processing step in the conventional method, and installation space can be reduced, and equipment and construction costs can be reduced. It is possible to stably produce good and inexpensive granulated dry sludge. In addition, since the device can be simplified, complicated operation management is not required.
Work and costs related to maintenance can be reduced.
Further, since the operation management is easy and easy to control, it is possible to stably produce granulated dry sludge having a desired moisture content in which the sludge to be dried and the carbide are sufficiently mixed without performing complicated operation operations. As a result, a high-quality compost raw material (granulated dry sludge) can be secured.

Further, according to the present invention, since the granular or powdery carbide is supplied to the sludge to be dried and / or the sludge granulation and drying step, the granular or powdery carbide serving as a core is provided. Sludge can be stably and uniformly adhered to the peripheral surface of, and fine granular and high-quality dry sludge can be easily obtained.

Further, according to the present invention, since the heat energy discharged from the carbide generation step in the heat source supply step is supplied to the heating section in the sludge granulation and drying step, waste heat from the carbide generation step is reduced. Since the heat source can be effectively used and a dedicated heat source for the heating unit is unnecessary or can be reduced, it is economical and can save resources and energy.

[Brief description of the drawings]

FIG. 1 is a basic configuration 1 of a sludge granulation and drying apparatus according to the present invention.
FIG.

FIG. 2 is a basic configuration 2 of a sludge granulation and drying apparatus according to the present invention.
FIG.

FIG. 3 is a block diagram showing Embodiment 1 of a sludge granulation and drying apparatus according to the present invention.

FIG. 4 is a perspective view specifically showing one embodiment of a sludge granulation and drying step in the sludge granulation and drying apparatus shown in FIG. 3;

FIG. 5 is a schematic diagram showing a state of granulation by dehydrated sludge and carbide by a sludge granulation and drying apparatus according to the present invention.

FIG. 6 is a block diagram showing one conventional method for obtaining granulated dry sludge.

FIG. 7 is a block diagram showing another conventional method for obtaining granulated dry sludge.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sludge dewatering machine 2 Carbonization device 3 Mixer 4 Dryer 5 Granulator 10 Sludge granulation drying process 11 Dry sludge supply process 12 Carbide supply process 13 Carbide generation process 14 Heat source supply process 20 Granulation dryer 21 Casing 21a Peripheral surface 22 Steam jacket 23 Steam inlet 24 Steam drain 25 Dewatered sludge supply pipe 26 Discharge conveyor 27 Sludge discharge port 28 Rotating shaft 29 Arm 30 Granulation fin 31 Drive motor 32 Rake 33 Baffle 34 Steam discharge port 40 Premix hopper 41 Transfer Conveyor 42 Centrifugal dehydrator 43 Dewatered cake storage hopper 44 Dewatered cake transfer conveyor 45 Carbonization furnace 46 Carbide storage hopper 47 First carbide transfer conveyor 48 Second carbide transfer conveyor 49 Heat exchanger 50 Heat energy supply pipe

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3L113 AA04 AB02 AC05 AC35 AC58 AC59 AC61 AC68 BA37 DA13 4D059 AA00 BB03 BD11 BD24 BD26 BE38 BJ03 BK09 CA10 CB01 CB18

Claims (2)

[Claims] 1. A drying tank having a heat transfer surface, a heating unit for heating the heat transfer surface of the drying tank, a rotating shaft provided inside the drying tank, and a sludge to be dried supported by the rotating shaft and dried. A sludge granulation and drying process comprising a plurality of rotating blades that are brought into contact with the heat transfer surface to the upper portion of the drying tank and a driving unit that rotates the rotating shaft; and supplying the sludge to be dried to the sludge granulation and drying process. A sludge granulation / drying apparatus comprising: a sludge supply step; and a carbide supply step of supplying carbide to the sludge granulation / drying step and / or the sludge supply step. 2. A drying tank having a heat transfer surface, a heating unit for heating the heat transfer surface of the drying tank, a rotating shaft provided inside the drying tank, and a sludge to be dried supported by the rotating shaft and dried. A sludge granulation and drying process comprising a plurality of rotating blades that are brought into contact with the heat transfer surface to the upper portion of the drying tank and a driving unit that rotates the rotating shaft; and supplying the sludge to be dried to the sludge granulation and drying process. A sludge supply step, a carbonization step of carbonizing organic matter, a carbide supply step of supplying the carbide generated in the carbonization step to the sludge granulation drying step and / or the sludge supply step, and a heat discharged from the carbonization step A sludge granulating and drying apparatus, comprising: a heat source supplying step of supplying energy to the heating section in the sludge granulating and drying step.